Verilog program for carry look ahead adder

The simplest form of adder is Ripple carry adder. But sometimes we might need adders which are faster than that. That is when Carry look ahead adders come to the rescue. By calculating all the carry's in advance, this type of adder achieves lower propagation delays and thus higher performance. The disadvantage comes from the fact that, as the size of inputs goes beyond 4 bits, the adder becomes much more complex.

In this post I have written a Verilog code for a 4 bit carry look ahead adder. A carry look ahead adder basically reduces the time complexity however increases the gate complexity as well as space complexity, hence its cost always increases. The Propagate Carry is produced when atleast one of A and B is 1 or whenever there is an input carry then the input carry is propagated. It is because whenever two bits are gonna be added then Generate and Propagate will determine whether the carry will generate of input carry will propagate.

Thus when no Propagation is required addition takes place without waiting for the ripple carry. To determine Propagate we have. The Propagate Group is. CLA uut. Share this: Twitter Facebook. Like this: Like Loading Working for me hereDo check that module name and instantiated module name inside test bench is sameMy module name here is CLA Like Like. May need it may not. Improve this question. Add a comment. Active Oldest Votes. Improve this answer. Thank you this really helps alot , behavioral modeling is better I agree but my professor wants this in structural — gps.

Structural is okay till you don't get confused in it. Your snippet has gate instance name related issues that's written in my answer. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog. Podcast Making Agile work for data science.

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